A Grain of Salt: The Science and Pseudoscience of What We Eat

A Grain of Salt: The Science and Pseudoscience of What We Eat

by Joe Schwarcz


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“This enlightening collection offers every reader something new to learn and marvel over.” — Booklist

Bestselling popular science author Dr. Joe Schwarcz debunks the baloney and serves up the raw facts in this appetizing collection about the things we eat

Eating has become a confusing experience. Should we follow a keto diet? Is sugar the next tobacco? Does fermented cabbage juice cure disease? Are lectins toxic? Is drinking poppy seed tea risky? What’s with probiotics? Can packaging contaminate food? Should our nuts be activated? What is cockroach milk?

We all have questions, and Dr. Joe Schwarcz has the answers, some of which will astonish you. This collection is guaranteed to satisfy your hunger for palatable and relevant scientific information as Dr. Joe separates fact from fiction with an assortment of new and updated articles about what to eat, what not to eat, and how to recognize the scientific basis of food chemistry.

Product Details

ISBN-13: 9781770414754
Publisher: ECW Press
Publication date: 10/08/2019
Pages: 312
Sales rank: 839,642
Product dimensions: 5.50(w) x 8.20(h) x 0.80(d)

About the Author

Dr. Joe Schwarcz is director of McGill University’s Office for Science and Society, dedicated to demystifying science and separating sense from nonsense. He is a popular lecturer, both to students and to the larger public. He hosts The Dr. Joe Show on Montreal radio and is the author of 16 bestselling titles. Dr. Joe lives in Montreal, Quebec.

Read an Excerpt


Fruits of the Internet

When I graduated university, my parents gave me a very special gift: a set of the renowned Encyclopedia Britannica! It had the answer to virtually every question I came across and was fun to just browse through. The last time I picked up one of those heavy volumes was about twenty years ago. By then, the Internet and the tsunami of information it brought to our fingertips had appeared on the scene.

Every day, I witness both the positive and negative power the web can unleash. I'm continuously flooded with questions that can be traced back to some item seen on the web. You don't even have to watch television anymore because significant clips, or entire programs, are just a few keystrokes away. A glance at just a few of the hundred or so questions that come my way during a single week affords insight into what is on the public mind. So let's have a go.

I always know what Dr. Mehmet Oz has been up to because my email inbox boils over with questions about his latest antics. Judging by the number of questions I got about monk fruit, it was clear that Oz had been trying to sweeten people's lives with this alternative to artificial sweeteners. We love sweets, but we worry, justifiably, about consuming too much sugar, and less justifiably, about its artificial replacements. The market is ripe for products that can be promoted as "natural no calorie sweeteners." Monk fruit extracts happen to fit the bill.

Legend has it that the fruit, commonly known by its Chinese name, luo han guo, was first cultivated by Buddhist monks back in the thirteenth century for its supposed fever-reducing and cough-relieving properties. Folklore also has monk fruit extending life, with claims that the counties in China where the fruit is grown for commercial purposes have an unusual number of centenarians. This has never been confirmed, and neither do we know whether the fruit is routinely consumed by the population there.

Various preparations of the fruit are sold in China with claims of moistening the lungs, eliminating phlegm, stopping cough, relieving sunstroke, and promoting bowel movements. While the efficacy of monk fruit as a medicine is questionable, the sweetness of its juice is not. This, however, did not arouse scientists' curiosity until the 1970s, when expanding waistlines led to expanding markets for noncaloric sweeteners. Analysis revealed that monk fruit contained five closely related compounds called mogrosides that are some 250 to 400 times sweeter than sugar. These can be extracted from the juice and processed into a powder to be used as a sweetening agent. Because of the high degree of sweetness, very little of the monk fruit extract is required, so it can be labeled as noncaloric. Although there have been no extensive safety studies, the U.S. Food and Drug Administration has classified monk fruit preparations as generally recognized as safe, or GRAS.

McNeil Nutritionals has now introduced monk fruit extract as a "no calorie sweetener" under the name Nectresse. In order to provide volume and appropriate texture, the extract is blended with a small amount of erythritol (a sugar alcohol), sugar, and molasses. These contribute fewer than five calories per serving, which is the limit for a product to be labeled as "containing no calories." I'd have no problem with trying this sweetener, and I'm sure many people who worry about artificial sweeteners will pounce on it. And people are worried about this one, sometimes for unusual reasons.

I was asked whether it is true that aspartame is made from the waste of certain bacteria. Actually, it sort of is, but that is irrelevant. Enzymes churned out by bacteria are commonly used to produce chemicals. Just think of adding Lactobacillus bulgaricus to milk to produce lactic acid and thereby yogurt. Or using genetically modified bacteria to make insulin or human growth hormone to treat diabetes and dwarfism. In the case of aspartame, Bacillus thermoproteolyticus is used to join together the two amino acids that make up aspartame. I suspect the question was asked because of concern that bacterial waste implies some sort of safety issue. It does not. The safety of a product does not depend on the route used to produce it; it is established by extensively studying it in the laboratory, in animal models, and by monitoring its use in humans.

Then there was a question about whether ripe bananas, full of black spots, have anticancer properties. The answer is simple: no. The daft banana story was based on a Japanese study reported in an obscure journal that involved injecting banana extract into the peritoneal cavity of rodents. Why this was done isn't clear. Probably because nobody had done it before. Scientists will be scientists. So what did they find? A slight increase in the animals' production of tumor necrosis factor (TNF), which as the name suggests, can have antitumor effects. But it can also have negative effects, such as exacerbating arthritis. In any case, this rodent study has no relevance to humans. We eat bananas; we don't mainline them. Furthermore, the circulating email suggests that bananas contain TNF, which is nonsense. Even if they did, it would not matter because this is a protein that would be broken down during digestion. Bananas make for a great snack, but there is no point in looking for spotted ones with the hopes of preventing cancer.

Now for the really weird. A worried woman asked if it is safe to drink milk when she travels to the U.S. Why? She had heard that women who drink milk from cows treated with bovine somatotropin to increase milk production are at risk for growing mustaches. Apparently, that story came from some Russian official who claimed that American milk causes women to develop male sexual characteristics. What a load of twaddle. Bovine somatotropin is not bioactive in humans. The only mustache you'll get by drinking milk is made of milk.

Next question. How do I know my answers are reasonable? Because the Internet allows me to search virtually all the published literature without leaving my desk. Clearly, the era of the printed encyclopedia is over. Although I was emotionally attached to my copy, it was taking up so much space that I decided to give it away. Nobody wanted it. A sign of the times.


What's for Dinner?

So, what should we have for dinner? It seems a simple question. But it is ever difficult to answer! Unfortunately, tasty and healthy don't always coincide. And just what is "healthy," anyway?

For close to forty years, I've pored through countless research papers and media accounts about food and nutrition. I've interviewed some of the world's top researchers in this area. My shelves sag with the weight of dozens and dozens of books on the subject, and this is the second book I've written myself that deals exclusively with food. My fifteen other books deal with plenty of nutritional connections as well. And even after all that, I'm still mystified about what we should have for dinner. But not completely. The wheat is slowly being separated from the chaff.

One thing is for sure: there's no shortage of nutritional information or opinions about what we should eat. Dr. Robert Lustig, a pediatric neuroendocrinologist at the University of California, believes that many health problems, obesity in particular, can be traced to consuming too much fructose. His video on the subject has gone "viral." University of Missouri professor Frederick vom Saal is of the opinion that obesity can be linked to bisphenol A, a chemical that can leach from the lining of canned foods. Dermatologist Dr. Robert Bibb, in his book Deadly Dairy Deception, makes a case for dairy products being the cause of prostate and breast cancer. Dr. Neal Barnard, president of the Physicians Committee for Responsible Medicine, goes even further in Eat Right, Live Longer, claiming that salvation lies in avoiding all animal products.

Cardiologist Dr. William Davis sees no problem with meat but sees wheat as the real bogeyman. According to him, the grain's polypeptides cross the blood–brain barrier and interact with opiate receptors to induce a mild euphoria that in turn causes addiction to wheat. As he describes in his bestselling book Wheat Belly, this results in fluctuating blood sugar levels that then create hunger and lead to obesity as well as numerous other health problems. How does Davis know all this? Apparently, his patients lose weight on a wheat-free diet and recover from all sorts of diseases. Has he published any of this in peer-reviewed journals? Not that I can find.

Davis would probably find a kindred spirit in Dr. Drew Ramsey, a clinical professor of psychiatry at Columbia University in New York. His book is called The Happiness Diet: A Nutritional Prescription for a Sharp Brain, Balanced Mood, and Lean, Energized Body. What is that wondrous prescription? It seems simple enough. If you want to be happy, stay away from bagels. According to Dr. Ramsey, "At first bagels boost a person's energy, but after a few hours you come crashing down looking for another fix in the modern American diet. That crash can cause people to feel irritable, lightheaded, or sad." Really? Maybe if they eat American bagels. I think legions of happy Montreal bagel lovers would disagree.

Journalist Gary Taubes maintains that not only wheat, but all carbohydrates, should be limited. In Good Calories, Bad Calories, he has gathered a massive amount of information to "prove" that excessive consumption of carbohydrates is the cause of heart disease, cancer, Alzheimer's disease, and type 2 diabetes. He advises against a low-fat diet. Dr. Dean Ornish, in Eat More, Weigh Less, would take issue with Taubes. He puts his cardiac patients on an extremely low-fat, high-complex-carbohydrate diet and has evidence that deposits in arteries actually regress.

I could go on and on about all the dietary advice that floods us. In Soy Smart Health, Dr. Neil Solomon claims that eating soy can decrease the risk of breast cancer, heart disease, and osteoporosis, while in The Whole Soy Story, Dr. Kaayla Daniel links soy to malnutrition, digestive problems, thyroid dysfunction, cognitive decline, reproductive disorders, heart disease, and cancer. Go figure.

Other authors suggest that our health is being undermined by monosodium glutamate (MSG) or artificial sweeteners or trans fats or pesticide residues or cooking in Teflon pans or genetically modified organisms or chlorinated water or acrylamide or phthalates or hormone residues or … or … or … And there is no lack of advice about how to get our health back on track. All we have to do is drink some esoteric juice, pop some sort of dietary supplement, gorge on some superfood, or eat like the Greeks or Chinese. So who do we listen to? The "experts" can't all be right.

When I throw all the divergent opinions into my mental flask and distill the essence, I come up with something like The Okinawa Diet Plan. This fascinating and very well-researched book chronicles the lifestyle habits of the longest-lived population in the world. We're not looking at some mythical Shangri-La here. In the Japanese islands of Okinawa, we have our sights on a people whose unusual longevity and good health is well documented. So is the fact that Okinawans do not gain significant weight as they age! Why? Because they consume 1,600 calories a day, at least 500 less than we do. And they do this while eating half a pound more food. It's all a matter of what sort of food: no hamburgers, hot dogs, or smoked meat here. And no soda pop. But they do eat plenty of food with very few calories per gram.

The lower the calorie density, the more food can be eaten without gaining weight. Basically, this means a plant-based diet. For example, broccoli, mushrooms, and carrots check in at about 0.4 calories per gram, tofu at 0.7, bread or meat, of which Okinawans eat very little, at about 3.0, and oils weigh in at 8.8. Michael Pollan, in his popular book The Omnivore's Dilemma, echoes the Okinawan way of eating: "Eat food. Not too much. Mostly plants." Dr. Shawn Baker, author of the Carnivore Diet, would not agree. Oh well …


Chrono Nutrition

"Eat breakfast yourself, share lunch with a friend, and give dinner away to the enemy" emerged as a proverb in the sixteenth century. That was quite a change from the warning that physicians had been giving since the Middle Ages about breakfast being detrimental to health. You would think that by now, with all the research that has been done, we would have figured out how calories should be distributed throughout the day. Not so.

In 2016, a study comparing the timing of major meals in different countries hit the headlines. In Guatemala and Poland, the largest meal is at lunch, with breakfast and dinner having equal calories. In France, Switzerland, and Italy, breakfasts are small, suppers somewhat larger, but the biggest meal is at lunch. Swedes eat small lunches and their breakfasts and suppers have the same calorie content. Germans, Americans, Danes, Dutch, Belgians, and Canadians eat the largest meal at night. The conclusion that researchers distilled out of these observations was that large evening meals are linked with obesity. But there are caveats. There was insufficient data on snacking, which may contribute to weight gain. Also, it may be that people who eat smaller suppers are more active, perhaps hitting the gym in the evening.

The benefits of eating the largest meal of the day in the morning are supported by a 2017 study that involved over 50,000 Seventh-Day Adventists. They were asked to fill out questionnaires every two years about their dietary habits, physical activity, meal frequency, major health events and changes in body weight. Subjects who ate the largest meal early in the day tended to have a lower body mass index than those whose largest meals were lunch or dinner. Perhaps the most interesting finding was that the lowest body mass index was found in people who ate breakfast and lunch but then did not eat again until the next morning, fasting for some eighteen to nineteen hours.

Extrapolating these findings to the general population is difficult because Seventh-Day Adventists have quite a different lifestyle from the average person. They consume no alcohol, eat less meat, and many are vegetarian. Still, the fasting aspect is interesting. With a steady supply of carbohydrates being cut off, the body undergoes a metabolic shift and starts using fat as fuel instead of carbohydrates, leading to fat loss.

The benefit of a large breakfast and small supper gets a boost from a study in Israel that put overweight women on an unevenly distributed 1,400-calorie-a-day diet. Half the women consumed 700 calories at breakfast, 500 at lunch, and 200 at supper, with the other half following the diet in reverse order. Both groups lost weight, but those who ate the large breakfast lost two and a half times more weight and lost more belly fat. Furthermore, their fasting glucose levels improved. It seems that when it comes to weight loss, when you eat may be as important as what you eat! At least according to this study.

A mouse study further supports the importance of "chrono nutrition," the idea that timing of meals has an effect on physiology. When mice are given unlimited access to a high-fat diet they become obese in about ten weeks and develop high blood cholesterol and insulin resistance. However, when they have access to the same diet for only eight hours a day, they do not become obese or diabetic even though they consume the same number of calories as the mice that have free access to food.

More evidence about the benefits of restricting calories according to a certain time frame comes from a study in which fifty people were told that they could eat anything they wanted for a month except for five days when they would be allowed only about 1,000 calories. After three months, fasting blood sugar, cholesterol, triglycerides, abdominal fat, and markers for some cancers improved significantly when compared with a control group.

Intriguing results have also been found for the 5:2 diet, in which people eat whatever they want for five days and then for two consecutive days limit their diet to 500 calories. There is better glucose regulation and greater loss of belly fat when compared with people who consume the same calories evenly distributed through the week. On the other hand, Courtney Peterson of the University of Alabama found that there was nothing special about squeezing all your daily meals into a brief time slot. She had one group of men eat all their meals within a six-hour period, while a control group consumed the same number of calories over twelve hours. If there were something physiologically special associated with fasting, men in the experimental group should have lost weight. They did not. Peterson's conclusion was that people who lose weight on an "intermittent fasting" diet do so because they end up eating less.


Excerpted from "A Grain of Salt"
by .
Copyright © 2019 Joe Schwarcz.
Excerpted by permission of ECW PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

Table of Contents

Also by Dr. Joe Schwarcz,
Fruits of the Internet,
What's for Dinner?,
Chrono Nutrition,
Advice about Food Is Sometimes Half-Baked,
Dining on Liquid Gold,
Some Beefs with Beef,
Count Your Way to Good Health,
Beating the Odds with Beets,
Swallowing Blueberries, Apples, and Hype,
Fiber and Graham,
Keto Surprises,
The Much-Maligned Egg,
Putrid Intestinal Guck?,
Microbes in the Gut,
A Culture Lesson,
The Pros of Probiotics Questioned,
Eat Like the Hadza,
The Food of the Gods,
Pond Scum for Health?,
Cockroach Milk,
Hot Dog Follies,
About That French Paradox,
Sugar's Effects Are Not So Sweet,
Taxing Sugar,
Sugar and the Brain,
How Splendid Is Splenda?,
Tom Brady's Alkaline Twaddle,
Silly Jilly,
The Dirt on Clean Eating,
Medical Medium,
Spare Me the Wheatgrass Enzymes,
Raw Water Nonsense,
Soured on Lemon Juice,
Matcha and Maca,
The Saga of Kosher Coke,
FCKD UP Is Gone. Good Riddance.,
Poppy Seed Tea,
Activated Nuts,
Are Lectins Nutritional Criminals?,
Weight Loss Supplements,
Antioxidant Hoopla,
Mystery of the Green Bread,
Butchering Science,
Food Wraps,
It's in the Can!,
Moscow Mule,
Tilapia and the Poop Connection,
Jellyfish Protein and Brain Function,
Hawking Brain Supplements,
Advanced Glycation End Products,
Sniffing for Fenugreek Effects,
Questioning Phosphates,
A Tale of Two Cantaloupes,
Confrontation with E. coli Is a Nasty Business,
Smoked Meat,
The Secret Life of Bagels,
Oh, That Gluten!,
An Ode to the Oat,
I'm a Bread and Propionates Man,
Agitate for Ice Cream,
Turkish Ice Cream Is Bad News for Orchids,
Say "Cheese",
Chew on This,
Thinking about Coconut Oil,
What's in a Vitamin Name?,
Man Cannot Live on Corn Alone,
Lessons from Popeye,
Dietary Supplements: To Take or Not to Take?,
The Cold Facts about Vitamin C,
Free Radicals Bad, Antioxidants Good: Is That So?,
To Label or Not to Label, That Is the Question!,
Scientists Smell a Rat in French GMO Rat Study,
From Twitching Worms to Non-Browning Apples,
The Saga of Golden Rice,
An Antidote to the Poisonous Tomato Legend,
Organic Agriculture,
Pesticide Problems,
The Evolution of Herbicides,
Science by Petition,
A Grain of Salt,
The No Conclusion Conclusion,
About the Author,

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